Actually I met this problem the first time I tried Galera, by using 'scripts/command.sh start'. I configured three Galera instance named home{0,1,2}. Instance home0 is started first, then home{1,2} are started simultaneously and request state in SST. Usually home2 instance failed with following message:

cat: /dev/shm/galera2/mysql/var//rsync_sst.pid: No such file or directory